sound/core/pcm_lib.c

   1 /*
   2  *  Digital Audio (PCM) abstract layer
   3  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
   4  *                   Abramo Bagnara <abramo@alsa-project.org>
   5  *
   6  *
   7  *   This program is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License as published by
   9  *   the Free Software Foundation; either version 2 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This program is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with this program; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  *
  21  */
  22
  23 #include <linux/slab.h>
  24 #include <linux/sched/signal.h>
  25 #include <linux/time.h>
  26 #include <linux/math64.h>
  27 #include <linux/export.h>
  28 #include <sound/core.h>
  29 #include <sound/control.h>
  30 #include <sound/tlv.h>
  31 #include <sound/info.h>
  32 #include <sound/pcm.h>
  33 #include <sound/pcm_params.h>
  34 #include <sound/timer.h>
  35
  36 #include "pcm_local.h"
  37
  38 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
  39 #define CREATE_TRACE_POINTS
  40 #include "pcm_trace.h"
  41 #else
  42 #define trace_hwptr(substream, pos, in_interrupt)
  43 #define trace_xrun(substream)
  44 #define trace_hw_ptr_error(substream, reason)
  45 #endif
  46
  47 static int fill_silence_frames(struct snd_pcm_substream *substream,
  48                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames);
  49
  50 /*
  51  * fill ring buffer with silence
  52  * runtime->silence_start: starting pointer to silence area
  53  * runtime->silence_filled: size filled with silence
  54  * runtime->silence_threshold: threshold from application
  55  * runtime->silence_size: maximal size from application
  56  *
  57  * when runtime->silence_size >= runtime->boundary - fill processed area with silence immediately
  58  */
  59 void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr)
  60 {
  61         struct snd_pcm_runtime *runtime = substream->runtime;
  62         snd_pcm_uframes_t frames, ofs, transfer;
  63         int err;
  64
  65         if (runtime->silence_size < runtime->boundary) {
  66                 snd_pcm_sframes_t noise_dist, n;
  67                 if (runtime->silence_start != runtime->control->appl_ptr) {
  68                         n = runtime->control->appl_ptr - runtime->silence_start;
  69                         if (n < 0)
  70                                 n += runtime->boundary;
  71                         if ((snd_pcm_uframes_t)n < runtime->silence_filled)
  72                                 runtime->silence_filled -= n;
  73                         else
  74                                 runtime->silence_filled = 0;
  75                         runtime->silence_start = runtime->control->appl_ptr;
  76                 }
  77                 if (runtime->silence_filled >= runtime->buffer_size)
  78                         return;
  79                 noise_dist = snd_pcm_playback_hw_avail(runtime) + runtime->silence_filled;
  80                 if (noise_dist >= (snd_pcm_sframes_t) runtime->silence_threshold)
  81                         return;
  82                 frames = runtime->silence_threshold - noise_dist;
  83                 if (frames > runtime->silence_size)
  84                         frames = runtime->silence_size;
  85         } else {
  86                 if (new_hw_ptr == ULONG_MAX) {  /* initialization */
  87                         snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
  88                         if (avail > runtime->buffer_size)
  89                                 avail = runtime->buffer_size;
  90                         runtime->silence_filled = avail > 0 ? avail : 0;
  91                         runtime->silence_start = (runtime->status->hw_ptr +
  92                                                   runtime->silence_filled) %
  93                                                  runtime->boundary;
  94                 } else {
  95                         ofs = runtime->status->hw_ptr;
  96                         frames = new_hw_ptr - ofs;
  97                         if ((snd_pcm_sframes_t)frames < 0)
  98                                 frames += runtime->boundary;
  99                         runtime->silence_filled -= frames;
 100                         if ((snd_pcm_sframes_t)runtime->silence_filled < 0) {
 101                                 runtime->silence_filled = 0;
 102                                 runtime->silence_start = new_hw_ptr;
 103                         } else {
 104                                 runtime->silence_start = ofs;
 105                         }
 106                 }
 107                 frames = runtime->buffer_size - runtime->silence_filled;
 108         }
 109         if (snd_BUG_ON(frames > runtime->buffer_size))
 110                 return;
 111         if (frames == 0)
 112                 return;
 113         ofs = runtime->silence_start % runtime->buffer_size;
 114         while (frames > 0) {
 115                 transfer = ofs + frames > runtime->buffer_size ? runtime->buffer_size - ofs : frames;
 116                 err = fill_silence_frames(substream, ofs, transfer);
 117                 snd_BUG_ON(err < 0);
 118                 runtime->silence_filled += transfer;
 119                 frames -= transfer;
 120                 ofs = 0;
 121         }
 122 }
 123
 124 #ifdef CONFIG_SND_DEBUG
 125 void snd_pcm_debug_name(struct snd_pcm_substream *substream,
 126                            char *name, size_t len)
 127 {
 128         snprintf(name, len, "pcmC%dD%d%c:%d",
 129                  substream->pcm->card->number,
 130                  substream->pcm->device,
 131                  substream->stream ? 'c' : 'p',
 132                  substream->number);
 133 }
 134 EXPORT_SYMBOL(snd_pcm_debug_name);
 135 #endif
 136
 137 #define XRUN_DEBUG_BASIC        (1<<0)
 138 #define XRUN_DEBUG_STACK        (1<<1)  /* dump also stack */
 139 #define XRUN_DEBUG_JIFFIESCHECK (1<<2)  /* do jiffies check */
 140
 141 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 142
 143 #define xrun_debug(substream, mask) \
 144                         ((substream)->pstr->xrun_debug & (mask))
 145 #else
 146 #define xrun_debug(substream, mask)     0
 147 #endif
 148
 149 #define dump_stack_on_xrun(substream) do {                      \
 150                 if (xrun_debug(substream, XRUN_DEBUG_STACK))    \
 151                         dump_stack();                           \
 152         } while (0)
 153
 154 static void xrun(struct snd_pcm_substream *substream)
 155 {
 156         struct snd_pcm_runtime *runtime = substream->runtime;
 157
 158         trace_xrun(substream);
 159         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE)
 160                 snd_pcm_gettime(runtime, (struct timespec *)&runtime->status->tstamp);
 161         snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
 162         if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {
 163                 char name[16];
 164                 snd_pcm_debug_name(substream, name, sizeof(name));
 165                 pcm_warn(substream->pcm, "XRUN: %s\n", name);
 166                 dump_stack_on_xrun(substream);
 167         }
 168 }
 169
 170 #ifdef CONFIG_SND_PCM_XRUN_DEBUG
 171 #define hw_ptr_error(substream, in_interrupt, reason, fmt, args...)     \
 172         do {                                                            \
 173                 trace_hw_ptr_error(substream, reason);  \
 174                 if (xrun_debug(substream, XRUN_DEBUG_BASIC)) {          \
 175                         pr_err_ratelimited("ALSA: PCM: [%c] " reason ": " fmt, \
 176                                            (in_interrupt) ? 'Q' : 'P', ##args); \
 177                         dump_stack_on_xrun(substream);                  \
 178                 }                                                       \
 179         } while (0)
 180
 181 #else /* ! CONFIG_SND_PCM_XRUN_DEBUG */
 182
 183 #define hw_ptr_error(substream, fmt, args...) do { } while (0)
 184
 185 #endif
 186
 187 int snd_pcm_update_state(struct snd_pcm_substream *substream,
 188                          struct snd_pcm_runtime *runtime)
 189 {
 190         snd_pcm_uframes_t avail;
 191
 192         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 193                 avail = snd_pcm_playback_avail(runtime);
 194         else
 195                 avail = snd_pcm_capture_avail(runtime);
 196         if (avail > runtime->avail_max)
 197                 runtime->avail_max = avail;
 198         if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
 199                 if (avail >= runtime->buffer_size) {
 200                         snd_pcm_drain_done(substream);
 201                         return -EPIPE;
 202                 }
 203         } else {
 204                 if (avail >= runtime->stop_threshold) {
 205                         xrun(substream);
 206                         return -EPIPE;
 207                 }
 208         }
 209         if (runtime->twake) {
 210                 if (avail >= runtime->twake)
 211                         wake_up(&runtime->tsleep);
 212         } else if (avail >= runtime->control->avail_min)
 213                 wake_up(&runtime->sleep);
 214         return 0;
 215 }
 216
 217 static void update_audio_tstamp(struct snd_pcm_substream *substream,
 218                                 struct timespec *curr_tstamp,
 219                                 struct timespec *audio_tstamp)
 220 {
 221         struct snd_pcm_runtime *runtime = substream->runtime;
 222         u64 audio_frames, audio_nsecs;
 223         struct timespec driver_tstamp;
 224
 225         if (runtime->tstamp_mode != SNDRV_PCM_TSTAMP_ENABLE)
 226                 return;
 227
 228         if (!(substream->ops->get_time_info) ||
 229                 (runtime->audio_tstamp_report.actual_type ==
 230                         SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 231
 232                 /*
 233                  * provide audio timestamp derived from pointer position
 234                  * add delay only if requested
 235                  */
 236
 237                 audio_frames = runtime->hw_ptr_wrap + runtime->status->hw_ptr;
 238
 239                 if (runtime->audio_tstamp_config.report_delay) {
 240                         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 241                                 audio_frames -=  runtime->delay;
 242                         else
 243                                 audio_frames +=  runtime->delay;
 244                 }
 245                 audio_nsecs = div_u64(audio_frames * 1000000000LL,
 246                                 runtime->rate);
 247                 *audio_tstamp = ns_to_timespec(audio_nsecs);
 248         }
 249         runtime->status->audio_tstamp = *audio_tstamp;
 250         runtime->status->tstamp = *curr_tstamp;
 251
 252         /*
 253          * re-take a driver timestamp to let apps detect if the reference tstamp
 254          * read by low-level hardware was provided with a delay
 255          */
 256         snd_pcm_gettime(substream->runtime, (struct timespec *)&driver_tstamp);
 257         runtime->driver_tstamp = driver_tstamp;
 258 }
 259
 260 static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
 261                                   unsigned int in_interrupt)
 262 {
 263         struct snd_pcm_runtime *runtime = substream->runtime;
 264         snd_pcm_uframes_t pos;
 265         snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
 266         snd_pcm_sframes_t hdelta, delta;
 267         unsigned long jdelta;
 268         unsigned long curr_jiffies;
 269         struct timespec curr_tstamp;
 270         struct timespec audio_tstamp;
 271         int crossed_boundary = 0;
 272
 273         old_hw_ptr = runtime->status->hw_ptr;
 274
 275         /*
 276          * group pointer, time and jiffies reads to allow for more
 277          * accurate correlations/corrections.
 278          * The values are stored at the end of this routine after
 279          * corrections for hw_ptr position
 280          */
 281         pos = substream->ops->pointer(substream);
 282         curr_jiffies = jiffies;
 283         if (runtime->tstamp_mode == SNDRV_PCM_TSTAMP_ENABLE) {
 284                 if ((substream->ops->get_time_info) &&
 285                         (runtime->audio_tstamp_config.type_requested != SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)) {
 286                         substream->ops->get_time_info(substream, &curr_tstamp,
 287                                                 &audio_tstamp,
 288                                                 &runtime->audio_tstamp_config,
 289                                                 &runtime->audio_tstamp_report);
 290
 291                         /* re-test in case tstamp type is not supported in hardware and was demoted to DEFAULT */
 292                         if (runtime->audio_tstamp_report.actual_type == SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT)
 293                                 snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 294                 } else
 295                         snd_pcm_gettime(runtime, (struct timespec *)&curr_tstamp);
 296         }
 297
 298         if (pos == SNDRV_PCM_POS_XRUN) {
 299                 xrun(substream);
 300                 return -EPIPE;
 301         }
 302         if (pos >= runtime->buffer_size) {
 303                 if (printk_ratelimit()) {
 304                         char name[16];
 305                         snd_pcm_debug_name(substream, name, sizeof(name));
 306                         pcm_err(substream->pcm,
 307                                 "invalid position: %s, pos = %ld, buffer size = %ld, period size = %ld\n",
 308                                 name, pos, runtime->buffer_size,
 309                                 runtime->period_size);
 310                 }
 311                 pos = 0;
 312         }
 313         pos -= pos % runtime->min_align;
 314         trace_hwptr(substream, pos, in_interrupt);
 315         hw_base = runtime->hw_ptr_base;
 316         new_hw_ptr = hw_base + pos;
 317         if (in_interrupt) {
 318                 /* we know that one period was processed */
 319                 /* delta = "expected next hw_ptr" for in_interrupt != 0 */
 320                 delta = runtime->hw_ptr_interrupt + runtime->period_size;
 321                 if (delta > new_hw_ptr) {
 322                         /* check for double acknowledged interrupts */
 323                         hdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 324                         if (hdelta > runtime->hw_ptr_buffer_jiffies/2 + 1) {
 325                                 hw_base += runtime->buffer_size;
 326                                 if (hw_base >= runtime->boundary) {
 327                                         hw_base = 0;
 328                                         crossed_boundary++;
 329                                 }
 330                                 new_hw_ptr = hw_base + pos;
 331                                 goto __delta;
 332                         }
 333                 }
 334         }
 335         /* new_hw_ptr might be lower than old_hw_ptr in case when */
 336         /* pointer crosses the end of the ring buffer */
 337         if (new_hw_ptr < old_hw_ptr) {
 338                 hw_base += runtime->buffer_size;
 339                 if (hw_base >= runtime->boundary) {
 340                         hw_base = 0;
 341                         crossed_boundary++;
 342                 }
 343                 new_hw_ptr = hw_base + pos;
 344         }
 345       __delta:
 346         delta = new_hw_ptr - old_hw_ptr;
 347         if (delta < 0)
 348                 delta += runtime->boundary;
 349
 350         if (runtime->no_period_wakeup) {
 351                 snd_pcm_sframes_t xrun_threshold;
 352                 /*
 353                  * Without regular period interrupts, we have to check
 354                  * the elapsed time to detect xruns.
 355                  */
 356                 jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 357                 if (jdelta < runtime->hw_ptr_buffer_jiffies / 2)
 358                         goto no_delta_check;
 359                 hdelta = jdelta - delta * HZ / runtime->rate;
 360                 xrun_threshold = runtime->hw_ptr_buffer_jiffies / 2 + 1;
 361                 while (hdelta > xrun_threshold) {
 362                         delta += runtime->buffer_size;
 363                         hw_base += runtime->buffer_size;
 364                         if (hw_base >= runtime->boundary) {
 365                                 hw_base = 0;
 366                                 crossed_boundary++;
 367                         }
 368                         new_hw_ptr = hw_base + pos;
 369                         hdelta -= runtime->hw_ptr_buffer_jiffies;
 370                 }
 371                 goto no_delta_check;
 372         }
 373
 374         /* something must be really wrong */
 375         if (delta >= runtime->buffer_size + runtime->period_size) {
 376                 hw_ptr_error(substream, in_interrupt, "Unexpected hw_ptr",
 377                              "(stream=%i, pos=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 378                              substream->stream, (long)pos,
 379                              (long)new_hw_ptr, (long)old_hw_ptr);
 380                 return 0;
 381         }
 382
 383         /* Do jiffies check only in xrun_debug mode */
 384         if (!xrun_debug(substream, XRUN_DEBUG_JIFFIESCHECK))
 385                 goto no_jiffies_check;
 386
 387         /* Skip the jiffies check for hardwares with BATCH flag.
 388          * Such hardware usually just increases the position at each IRQ,
 389          * thus it can't give any strange position.
 390          */
 391         if (runtime->hw.info & SNDRV_PCM_INFO_BATCH)
 392                 goto no_jiffies_check;
 393         hdelta = delta;
 394         if (hdelta < runtime->delay)
 395                 goto no_jiffies_check;
 396         hdelta -= runtime->delay;
 397         jdelta = curr_jiffies - runtime->hw_ptr_jiffies;
 398         if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
 399                 delta = jdelta /
 400                         (((runtime->period_size * HZ) / runtime->rate)
 401                                                                 + HZ/100);
 402                 /* move new_hw_ptr according jiffies not pos variable */
 403                 new_hw_ptr = old_hw_ptr;
 404                 hw_base = delta;
 405                 /* use loop to avoid checks for delta overflows */
 406                 /* the delta value is small or zero in most cases */
 407                 while (delta > 0) {
 408                         new_hw_ptr += runtime->period_size;
 409                         if (new_hw_ptr >= runtime->boundary) {
 410                                 new_hw_ptr -= runtime->boundary;
 411                                 crossed_boundary--;
 412                         }
 413                         delta--;
 414                 }
 415                 /* align hw_base to buffer_size */
 416                 hw_ptr_error(substream, in_interrupt, "hw_ptr skipping",
 417                              "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu/%lu, hw_ptr=%ld/%ld)\n",
 418                              (long)pos, (long)hdelta,
 419                              (long)runtime->period_size, jdelta,
 420                              ((hdelta * HZ) / runtime->rate), hw_base,
 421                              (unsigned long)old_hw_ptr,
 422                              (unsigned long)new_hw_ptr);
 423                 /* reset values to proper state */
 424                 delta = 0;
 425                 hw_base = new_hw_ptr - (new_hw_ptr % runtime->buffer_size);
 426         }
 427  no_jiffies_check:
 428         if (delta > runtime->period_size + runtime->period_size / 2) {
 429                 hw_ptr_error(substream, in_interrupt,
 430                              "Lost interrupts?",
 431                              "(stream=%i, delta=%ld, new_hw_ptr=%ld, old_hw_ptr=%ld)\n",
 432                              substream->stream, (long)delta,
 433                              (long)new_hw_ptr,
 434                              (long)old_hw_ptr);
 435         }
 436
 437  no_delta_check:
 438         if (runtime->status->hw_ptr == new_hw_ptr) {
 439                 update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 440                 return 0;
 441         }
 442
 443         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
 444             runtime->silence_size > 0)
 445                 snd_pcm_playback_silence(substream, new_hw_ptr);
 446
 447         if (in_interrupt) {
 448                 delta = new_hw_ptr - runtime->hw_ptr_interrupt;
 449                 if (delta < 0)
 450                         delta += runtime->boundary;
 451                 delta -= (snd_pcm_uframes_t)delta % runtime->period_size;
 452                 runtime->hw_ptr_interrupt += delta;
 453                 if (runtime->hw_ptr_interrupt >= runtime->boundary)
 454                         runtime->hw_ptr_interrupt -= runtime->boundary;
 455         }
 456         runtime->hw_ptr_base = hw_base;
 457         runtime->status->hw_ptr = new_hw_ptr;
 458         runtime->hw_ptr_jiffies = curr_jiffies;
 459         if (crossed_boundary) {
 460                 snd_BUG_ON(crossed_boundary != 1);
 461                 runtime->hw_ptr_wrap += runtime->boundary;
 462         }
 463
 464         update_audio_tstamp(substream, &curr_tstamp, &audio_tstamp);
 465
 466         return snd_pcm_update_state(substream, runtime);
 467 }
 468
 469 /* CAUTION: call it with irq disabled */
 470 int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
 471 {
 472         return snd_pcm_update_hw_ptr0(substream, 0);
 473 }
 474
 475 /**
 476  * snd_pcm_set_ops - set the PCM operators
 477  * @pcm: the pcm instance
 478  * @direction: stream direction, SNDRV_PCM_STREAM_XXX
 479  * @ops: the operator table
 480  *
 481  * Sets the given PCM operators to the pcm instance.
 482  */
 483 void snd_pcm_set_ops(struct snd_pcm *pcm, int direction,
 484                      const struct snd_pcm_ops *ops)
 485 {
 486         struct snd_pcm_str *stream = &pcm->streams[direction];
 487         struct snd_pcm_substream *substream;
 488
 489         for (substream = stream->substream; substream != NULL; substream = substream->next)
 490                 substream->ops = ops;
 491 }
 492
 493 EXPORT_SYMBOL(snd_pcm_set_ops);
 494
 495 /**
 496  * snd_pcm_sync - set the PCM sync id
 497  * @substream: the pcm substream
 498  *
 499  * Sets the PCM sync identifier for the card.
 500  */
 501 void snd_pcm_set_sync(struct snd_pcm_substream *substream)
 502 {
 503         struct snd_pcm_runtime *runtime = substream->runtime;
 504
 505         runtime->sync.id32[0] = substream->pcm->card->number;
 506         runtime->sync.id32[1] = -1;
 507         runtime->sync.id32[2] = -1;
 508         runtime->sync.id32[3] = -1;
 509 }
 510
 511 EXPORT_SYMBOL(snd_pcm_set_sync);
 512
 513 /*
 514  *  Standard ioctl routine
 515  */
 516
 517 static inline unsigned int div32(unsigned int a, unsigned int b,
 518                                  unsigned int *r)
 519 {
 520         if (b == 0) {
 521                 *r = 0;
 522                 return UINT_MAX;
 523         }
 524         *r = a % b;
 525         return a / b;
 526 }
 527
 528 static inline unsigned int div_down(unsigned int a, unsigned int b)
 529 {
 530         if (b == 0)
 531                 return UINT_MAX;
 532         return a / b;
 533 }
 534
 535 static inline unsigned int div_up(unsigned int a, unsigned int b)
 536 {
 537         unsigned int r;
 538         unsigned int q;
 539         if (b == 0)
 540                 return UINT_MAX;
 541         q = div32(a, b, &r);
 542         if (r)
 543                 ++q;
 544         return q;
 545 }
 546
 547 static inline unsigned int mul(unsigned int a, unsigned int b)
 548 {
 549         if (a == 0)
 550                 return 0;
 551         if (div_down(UINT_MAX, a) < b)
 552                 return UINT_MAX;
 553         return a * b;
 554 }
 555
 556 static inline unsigned int muldiv32(unsigned int a, unsigned int b,
 557                                     unsigned int c, unsigned int *r)
 558 {
 559         u_int64_t n = (u_int64_t) a * b;
 560         if (c == 0) {
 561                 snd_BUG_ON(!n);
 562                 *r = 0;
 563                 return UINT_MAX;
 564         }
 565         n = div_u64_rem(n, c, r);
 566         if (n >= UINT_MAX) {
 567                 *r = 0;
 568                 return UINT_MAX;
 569         }
 570         return n;
 571 }
 572
 573 /**
 574  * snd_interval_refine - refine the interval value of configurator
 575  * @i: the interval value to refine
 576  * @v: the interval value to refer to
 577  *
 578  * Refines the interval value with the reference value.
 579  * The interval is changed to the range satisfying both intervals.
 580  * The interval status (min, max, integer, etc.) are evaluated.
 581  *
 582  * Return: Positive if the value is changed, zero if it's not changed, or a
 583  * negative error code.
 584  */
 585 int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v)
 586 {
 587         int changed = 0;
 588         if (snd_BUG_ON(snd_interval_empty(i)))
 589                 return -EINVAL;
 590         if (i->min < v->min) {
 591                 i->min = v->min;
 592                 i->openmin = v->openmin;
 593                 changed = 1;
 594         } else if (i->min == v->min && !i->openmin && v->openmin) {
 595                 i->openmin = 1;
 596                 changed = 1;
 597         }
 598         if (i->max > v->max) {
 599                 i->max = v->max;
 600                 i->openmax = v->openmax;
 601                 changed = 1;
 602         } else if (i->max == v->max && !i->openmax && v->openmax) {
 603                 i->openmax = 1;
 604                 changed = 1;
 605         }
 606         if (!i->integer && v->integer) {
 607                 i->integer = 1;
 608                 changed = 1;
 609         }
 610         if (i->integer) {
 611                 if (i->openmin) {
 612                         i->min++;
 613                         i->openmin = 0;
 614                 }
 615                 if (i->openmax) {
 616                         i->max--;
 617                         i->openmax = 0;
 618                 }
 619         } else if (!i->openmin && !i->openmax && i->min == i->max)
 620                 i->integer = 1;
 621         if (snd_interval_checkempty(i)) {
 622                 snd_interval_none(i);
 623                 return -EINVAL;
 624         }
 625         return changed;
 626 }
 627
 628 EXPORT_SYMBOL(snd_interval_refine);
 629
 630 static int snd_interval_refine_first(struct snd_interval *i)
 631 {
 632         if (snd_BUG_ON(snd_interval_empty(i)))
 633                 return -EINVAL;
 634         if (snd_interval_single(i))
 635                 return 0;
 636         i->max = i->min;
 637         i->openmax = i->openmin;
 638         if (i->openmax)
 639                 i->max++;
 640         return 1;
 641 }
 642
 643 static int snd_interval_refine_last(struct snd_interval *i)
 644 {
 645         if (snd_BUG_ON(snd_interval_empty(i)))
 646                 return -EINVAL;
 647         if (snd_interval_single(i))
 648                 return 0;
 649         i->min = i->max;
 650         i->openmin = i->openmax;
 651         if (i->openmin)
 652                 i->min--;
 653         return 1;
 654 }
 655
 656 void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 657 {
 658         if (a->empty || b->empty) {
 659                 snd_interval_none(c);
 660                 return;
 661         }
 662         c->empty = 0;
 663         c->min = mul(a->min, b->min);
 664         c->openmin = (a->openmin || b->openmin);
 665         c->max = mul(a->max,  b->max);
 666         c->openmax = (a->openmax || b->openmax);
 667         c->integer = (a->integer && b->integer);
 668 }
 669
 670 /**
 671  * snd_interval_div - refine the interval value with division
 672  * @a: dividend
 673  * @b: divisor
 674  * @c: quotient
 675  *
 676  * c = a / b
 677  *
 678  * Returns non-zero if the value is changed, zero if not changed.
 679  */
 680 void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c)
 681 {
 682         unsigned int r;
 683         if (a->empty || b->empty) {
 684                 snd_interval_none(c);
 685                 return;
 686         }
 687         c->empty = 0;
 688         c->min = div32(a->min, b->max, &r);
 689         c->openmin = (r || a->openmin || b->openmax);
 690         if (b->min > 0) {
 691                 c->max = div32(a->max, b->min, &r);
 692                 if (r) {
 693                         c->max++;
 694                         c->openmax = 1;
 695                 } else
 696                         c->openmax = (a->openmax || b->openmin);
 697         } else {
 698                 c->max = UINT_MAX;
 699                 c->openmax = 0;
 700         }
 701         c->integer = 0;
 702 }
 703
 704 /**
 705  * snd_interval_muldivk - refine the interval value
 706  * @a: dividend 1
 707  * @b: dividend 2
 708  * @k: divisor (as integer)
 709  * @c: result
 710   *
 711  * c = a * b / k
 712  *
 713  * Returns non-zero if the value is changed, zero if not changed.
 714  */
 715 void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b,
 716                       unsigned int k, struct snd_interval *c)
 717 {
 718         unsigned int r;
 719         if (a->empty || b->empty) {
 720                 snd_interval_none(c);
 721                 return;
 722         }
 723         c->empty = 0;
 724         c->min = muldiv32(a->min, b->min, k, &r);
 725         c->openmin = (r || a->openmin || b->openmin);
 726         c->max = muldiv32(a->max, b->max, k, &r);
 727         if (r) {
 728                 c->max++;
 729                 c->openmax = 1;
 730         } else
 731                 c->openmax = (a->openmax || b->openmax);
 732         c->integer = 0;
 733 }
 734
 735 /**
 736  * snd_interval_mulkdiv - refine the interval value
 737  * @a: dividend 1
 738  * @k: dividend 2 (as integer)
 739  * @b: divisor
 740  * @c: result
 741  *
 742  * c = a * k / b
 743  *
 744  * Returns non-zero if the value is changed, zero if not changed.
 745  */
 746 void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
 747                       const struct snd_interval *b, struct snd_interval *c)
 748 {
 749         unsigned int r;
 750         if (a->empty || b->empty) {
 751                 snd_interval_none(c);
 752                 return;
 753         }
 754         c->empty = 0;
 755         c->min = muldiv32(a->min, k, b->max, &r);
 756         c->openmin = (r || a->openmin || b->openmax);
 757         if (b->min > 0) {
 758                 c->max = muldiv32(a->max, k, b->min, &r);
 759                 if (r) {
 760                         c->max++;
 761                         c->openmax = 1;
 762                 } else
 763                         c->openmax = (a->openmax || b->openmin);
 764         } else {
 765                 c->max = UINT_MAX;
 766                 c->openmax = 0;
 767         }
 768         c->integer = 0;
 769 }
 770
 771 /* ---- */
 772
 773
 774 /**
 775  * snd_interval_ratnum - refine the interval value
 776  * @i: interval to refine
 777  * @rats_count: number of ratnum_t
 778  * @rats: ratnum_t array
 779  * @nump: pointer to store the resultant numerator
 780  * @denp: pointer to store the resultant denominator
 781  *
 782  * Return: Positive if the value is changed, zero if it's not changed, or a
 783  * negative error code.
 784  */
 785 int snd_interval_ratnum(struct snd_interval *i,
 786                         unsigned int rats_count, const struct snd_ratnum *rats,
 787                         unsigned int *nump, unsigned int *denp)
 788 {
 789         unsigned int best_num, best_den;
 790         int best_diff;
 791         unsigned int k;
 792         struct snd_interval t;
 793         int err;
 794         unsigned int result_num, result_den;
 795         int result_diff;
 796
 797         best_num = best_den = best_diff = 0;
 798         for (k = 0; k < rats_count; ++k) {
 799                 unsigned int num = rats[k].num;
 800                 unsigned int den;
 801                 unsigned int q = i->min;
 802                 int diff;
 803                 if (q == 0)
 804                         q = 1;
 805                 den = div_up(num, q);
 806                 if (den < rats[k].den_min)
 807                         continue;
 808                 if (den > rats[k].den_max)
 809                         den = rats[k].den_max;
 810                 else {
 811                         unsigned int r;
 812                         r = (den - rats[k].den_min) % rats[k].den_step;
 813                         if (r != 0)
 814                                 den -= r;
 815                 }
 816                 diff = num - q * den;
 817                 if (diff < 0)
 818                         diff = -diff;
 819                 if (best_num == 0 ||
 820                     diff * best_den < best_diff * den) {
 821                         best_diff = diff;
 822                         best_den = den;
 823                         best_num = num;
 824                 }
 825         }
 826         if (best_den == 0) {
 827                 i->empty = 1;
 828                 return -EINVAL;
 829         }
 830         t.min = div_down(best_num, best_den);
 831         t.openmin = !!(best_num % best_den);
 832
 833         result_num = best_num;
 834         result_diff = best_diff;
 835         result_den = best_den;
 836         best_num = best_den = best_diff = 0;
 837         for (k = 0; k < rats_count; ++k) {
 838                 unsigned int num = rats[k].num;
 839                 unsigned int den;
 840                 unsigned int q = i->max;
 841                 int diff;
 842                 if (q == 0) {
 843                         i->empty = 1;
 844                         return -EINVAL;
 845                 }
 846                 den = div_down(num, q);
 847                 if (den > rats[k].den_max)
 848                         continue;
 849                 if (den < rats[k].den_min)
 850                         den = rats[k].den_min;
 851                 else {
 852                         unsigned int r;
 853                         r = (den - rats[k].den_min) % rats[k].den_step;
 854                         if (r != 0)
 855                                 den += rats[k].den_step - r;
 856                 }
 857                 diff = q * den - num;
 858                 if (diff < 0)
 859                         diff = -diff;
 860                 if (best_num == 0 ||
 861                     diff * best_den < best_diff * den) {
 862                         best_diff = diff;
 863                         best_den = den;
 864                         best_num = num;
 865                 }
 866         }
 867         if (best_den == 0) {
 868                 i->empty = 1;
 869                 return -EINVAL;
 870         }
 871         t.max = div_up(best_num, best_den);
 872         t.openmax = !!(best_num % best_den);
 873         t.integer = 0;
 874         err = snd_interval_refine(i, &t);
 875         if (err < 0)
 876                 return err;
 877
 878         if (snd_interval_single(i)) {
 879                 if (best_diff * result_den < result_diff * best_den) {
 880                         result_num = best_num;
 881                         result_den = best_den;
 882                 }
 883                 if (nump)
 884                         *nump = result_num;
 885                 if (denp)
 886                         *denp = result_den;
 887         }
 888         return err;
 889 }
 890
 891 EXPORT_SYMBOL(snd_interval_ratnum);
 892
 893 /**
 894  * snd_interval_ratden - refine the interval value
 895  * @i: interval to refine
 896  * @rats_count: number of struct ratden
 897  * @rats: struct ratden array
 898  * @nump: pointer to store the resultant numerator
 899  * @denp: pointer to store the resultant denominator
 900  *
 901  * Return: Positive if the value is changed, zero if it's not changed, or a
 902  * negative error code.
 903  */
 904 static int snd_interval_ratden(struct snd_interval *i,
 905                                unsigned int rats_count,
 906                                const struct snd_ratden *rats,
 907                                unsigned int *nump, unsigned int *denp)
 908 {
 909         unsigned int best_num, best_diff, best_den;
 910         unsigned int k;
 911         struct snd_interval t;
 912         int err;
 913
 914         best_num = best_den = best_diff = 0;
 915         for (k = 0; k < rats_count; ++k) {
 916                 unsigned int num;
 917                 unsigned int den = rats[k].den;
 918                 unsigned int q = i->min;
 919                 int diff;
 920                 num = mul(q, den);
 921                 if (num > rats[k].num_max)
 922                         continue;
 923                 if (num < rats[k].num_min)
 924                         num = rats[k].num_max;
 925                 else {
 926                         unsigned int r;
 927                         r = (num - rats[k].num_min) % rats[k].num_step;
 928                         if (r != 0)
 929                                 num += rats[k].num_step - r;
 930                 }
 931                 diff = num - q * den;
 932                 if (best_num == 0 ||
 933                     diff * best_den < best_diff * den) {
 934                         best_diff = diff;
 935                         best_den = den;
 936                         best_num = num;
 937                 }
 938         }
 939         if (best_den == 0) {
 940                 i->empty = 1;
 941                 return -EINVAL;
 942         }
 943         t.min = div_down(best_num, best_den);
 944         t.openmin = !!(best_num % best_den);
 945
 946         best_num = best_den = best_diff = 0;
 947         for (k = 0; k < rats_count; ++k) {
 948                 unsigned int num;
 949                 unsigned int den = rats[k].den;
 950                 unsigned int q = i->max;
 951                 int diff;
 952                 num = mul(q, den);
 953                 if (num < rats[k].num_min)
 954                         continue;
 955                 if (num > rats[k].num_max)
 956                         num = rats[k].num_max;
 957                 else {
 958                         unsigned int r;
 959                         r = (num - rats[k].num_min) % rats[k].num_step;
 960                         if (r != 0)
 961                                 num -= r;
 962                 }
 963                 diff = q * den - num;
 964                 if (best_num == 0 ||
 965                     diff * best_den < best_diff * den) {
 966                         best_diff = diff;
 967                         best_den = den;
 968                         best_num = num;
 969                 }
 970         }
 971         if (best_den == 0) {
 972                 i->empty = 1;
 973                 return -EINVAL;
 974         }
 975         t.max = div_up(best_num, best_den);
 976         t.openmax = !!(best_num % best_den);
 977         t.integer = 0;
 978         err = snd_interval_refine(i, &t);
 979         if (err < 0)
 980                 return err;
 981
 982         if (snd_interval_single(i)) {
 983                 if (nump)
 984                         *nump = best_num;
 985                 if (denp)
 986                         *denp = best_den;
 987         }
 988         return err;
 989 }
 990
 991 /**
 992  * snd_interval_list - refine the interval value from the list
 993  * @i: the interval value to refine
 994  * @count: the number of elements in the list
 995  * @list: the value list
 996  * @mask: the bit-mask to evaluate
 997  *
 998  * Refines the interval value from the list.
 999  * When mask is non-zero, only the elements corresponding to bit 1 are
1000  * evaluated.
1001  *
1002  * Return: Positive if the value is changed, zero if it's not changed, or a
1003  * negative error code.
1004  */
1005 int snd_interval_list(struct snd_interval *i, unsigned int count,
1006                       const unsigned int *list, unsigned int mask)
1007 {
1008         unsigned int k;
1009         struct snd_interval list_range;
1010
1011         if (!count) {
1012                 i->empty = 1;
1013                 return -EINVAL;
1014         }
1015         snd_interval_any(&list_range);
1016         list_range.min = UINT_MAX;
1017         list_range.max = 0;
1018         for (k = 0; k < count; k++) {
1019                 if (mask && !(mask & (1 << k)))
1020                         continue;
1021                 if (!snd_interval_test(i, list[k]))
1022                         continue;
1023                 list_range.min = min(list_range.min, list[k]);
1024                 list_range.max = max(list_range.max, list[k]);
1025         }
1026         return snd_interval_refine(i, &list_range);
1027 }
1028
1029 EXPORT_SYMBOL(snd_interval_list);
1030
1031 /**
1032  * snd_interval_ranges - refine the interval value from the list of ranges
1033  * @i: the interval value to refine
1034  * @count: the number of elements in the list of ranges
1035  * @ranges: the ranges list
1036  * @mask: the bit-mask to evaluate
1037  *
1038  * Refines the interval value from the list of ranges.
1039  * When mask is non-zero, only the elements corresponding to bit 1 are
1040  * evaluated.
1041  *
1042  * Return: Positive if the value is changed, zero if it's not changed, or a
1043  * negative error code.
1044  */
1045 int snd_interval_ranges(struct snd_interval *i, unsigned int count,
1046                         const struct snd_interval *ranges, unsigned int mask)
1047 {
1048         unsigned int k;
1049         struct snd_interval range_union;
1050         struct snd_interval range;
1051
1052         if (!count) {
1053                 snd_interval_none(i);
1054                 return -EINVAL;
1055         }
1056         snd_interval_any(&range_union);
1057         range_union.min = UINT_MAX;
1058         range_union.max = 0;
1059         for (k = 0; k < count; k++) {
1060                 if (mask && !(mask & (1 << k)))
1061                         continue;
1062                 snd_interval_copy(&range, &ranges[k]);
1063                 if (snd_interval_refine(&range, i) < 0)
1064                         continue;
1065                 if (snd_interval_empty(&range))
1066                         continue;
1067
1068                 if (range.min < range_union.min) {
1069                         range_union.min = range.min;
1070                         range_union.openmin = 1;
1071                 }
1072                 if (range.min == range_union.min && !range.openmin)
1073                         range_union.openmin = 0;
1074                 if (range.max > range_union.max) {
1075                         range_union.max = range.max;
1076                         range_union.openmax = 1;
1077                 }
1078                 if (range.max == range_union.max && !range.openmax)
1079                         range_union.openmax = 0;
1080         }
1081         return snd_interval_refine(i, &range_union);
1082 }
1083 EXPORT_SYMBOL(snd_interval_ranges);
1084
1085 static int snd_interval_step(struct snd_interval *i, unsigned int step)
1086 {
1087         unsigned int n;
1088         int changed = 0;
1089         n = i->min % step;
1090         if (n != 0 || i->openmin) {
1091                 i->min += step - n;
1092                 i->openmin = 0;
1093                 changed = 1;
1094         }
1095         n = i->max % step;
1096         if (n != 0 || i->openmax) {
1097                 i->max -= n;
1098                 i->openmax = 0;
1099                 changed = 1;
1100         }
1101         if (snd_interval_checkempty(i)) {
1102                 i->empty = 1;
1103                 return -EINVAL;
1104         }
1105         return changed;
1106 }
1107
1108 /* Info constraints helpers */
1109
1110 /**
1111  * snd_pcm_hw_rule_add - add the hw-constraint rule
1112  * @runtime: the pcm runtime instance
1113  * @cond: condition bits
1114  * @var: the variable to evaluate
1115  * @func: the evaluation function
1116  * @private: the private data pointer passed to function
1117  * @dep: the dependent variables
1118  *
1119  * Return: Zero if successful, or a negative error code on failure.
1120  */
1121 int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime, unsigned int cond,
1122                         int var,
1123                         snd_pcm_hw_rule_func_t func, void *private,
1124                         int dep, ...)
1125 {
1126         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1127         struct snd_pcm_hw_rule *c;
1128         unsigned int k;
1129         va_list args;
1130         va_start(args, dep);
1131         if (constrs->rules_num >= constrs->rules_all) {
1132                 struct snd_pcm_hw_rule *new;
1133                 unsigned int new_rules = constrs->rules_all + 16;
1134                 new = kcalloc(new_rules, sizeof(*c), GFP_KERNEL);
1135                 if (!new) {
1136                         va_end(args);
1137                         return -ENOMEM;
1138                 }
1139                 if (constrs->rules) {
1140                         memcpy(new, constrs->rules,
1141                                constrs->rules_num * sizeof(*c));
1142                         kfree(constrs->rules);
1143                 }
1144                 constrs->rules = new;
1145                 constrs->rules_all = new_rules;
1146         }
1147         c = &constrs->rules[constrs->rules_num];
1148         c->cond = cond;
1149         c->func = func;
1150         c->var = var;
1151         c->private = private;
1152         k = 0;
1153         while (1) {
1154                 if (snd_BUG_ON(k >= ARRAY_SIZE(c->deps))) {
1155                         va_end(args);
1156                         return -EINVAL;
1157                 }
1158                 c->deps[k++] = dep;
1159                 if (dep < 0)
1160                         break;
1161                 dep = va_arg(args, int);
1162         }
1163         constrs->rules_num++;
1164         va_end(args);
1165         return 0;
1166 }
1167
1168 EXPORT_SYMBOL(snd_pcm_hw_rule_add);
1169
1170 /**
1171  * snd_pcm_hw_constraint_mask - apply the given bitmap mask constraint
1172  * @runtime: PCM runtime instance
1173  * @var: hw_params variable to apply the mask
1174  * @mask: the bitmap mask
1175  *
1176  * Apply the constraint of the given bitmap mask to a 32-bit mask parameter.
1177  *
1178  * Return: Zero if successful, or a negative error code on failure.
1179  */
1180 int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1181                                u_int32_t mask)
1182 {
1183         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1184         struct snd_mask *maskp = constrs_mask(constrs, var);
1185         *maskp->bits &= mask;
1186         memset(maskp->bits + 1, 0, (SNDRV_MASK_MAX-32) / 8); /* clear rest */
1187         if (*maskp->bits == 0)
1188                 return -EINVAL;
1189         return 0;
1190 }
1191
1192 /**
1193  * snd_pcm_hw_constraint_mask64 - apply the given bitmap mask constraint
1194  * @runtime: PCM runtime instance
1195  * @var: hw_params variable to apply the mask
1196  * @mask: the 64bit bitmap mask
1197  *
1198  * Apply the constraint of the given bitmap mask to a 64-bit mask parameter.
1199  *
1200  * Return: Zero if successful, or a negative error code on failure.
1201  */
1202 int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1203                                  u_int64_t mask)
1204 {
1205         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1206         struct snd_mask *maskp = constrs_mask(constrs, var);
1207         maskp->bits[0] &= (u_int32_t)mask;
1208         maskp->bits[1] &= (u_int32_t)(mask >> 32);
1209         memset(maskp->bits + 2, 0, (SNDRV_MASK_MAX-64) / 8); /* clear rest */
1210         if (! maskp->bits[0] && ! maskp->bits[1])
1211                 return -EINVAL;
1212         return 0;
1213 }
1214 EXPORT_SYMBOL(snd_pcm_hw_constraint_mask64);
1215
1216 /**
1217  * snd_pcm_hw_constraint_integer - apply an integer constraint to an interval
1218  * @runtime: PCM runtime instance
1219  * @var: hw_params variable to apply the integer constraint
1220  *
1221  * Apply the constraint of integer to an interval parameter.
1222  *
1223  * Return: Positive if the value is changed, zero if it's not changed, or a
1224  * negative error code.
1225  */
1226 int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var)
1227 {
1228         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1229         return snd_interval_setinteger(constrs_interval(constrs, var));
1230 }
1231
1232 EXPORT_SYMBOL(snd_pcm_hw_constraint_integer);
1233
1234 /**
1235  * snd_pcm_hw_constraint_minmax - apply a min/max range constraint to an interval
1236  * @runtime: PCM runtime instance
1237  * @var: hw_params variable to apply the range
1238  * @min: the minimal value
1239  * @max: the maximal value
1240  *
1241  * Apply the min/max range constraint to an interval parameter.
1242  *
1243  * Return: Positive if the value is changed, zero if it's not changed, or a
1244  * negative error code.
1245  */
1246 int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
1247                                  unsigned int min, unsigned int max)
1248 {
1249         struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
1250         struct snd_interval t;
1251         t.min = min;
1252         t.max = max;
1253         t.openmin = t.openmax = 0;
1254         t.integer = 0;
1255         return snd_interval_refine(constrs_interval(constrs, var), &t);
1256 }
1257
1258 EXPORT_SYMBOL(snd_pcm_hw_constraint_minmax);
1259
1260 static int snd_pcm_hw_rule_list(struct snd_pcm_hw_params *params,
1261                                 struct snd_pcm_hw_rule *rule)
1262 {
1263         struct snd_pcm_hw_constraint_list *list = rule->private;
1264         return snd_interval_list(hw_param_interval(params, rule->var), list->count, list->list, list->mask);
1265 }
1266
1267
1268 /**
1269  * snd_pcm_hw_constraint_list - apply a list of constraints to a parameter
1270  * @runtime: PCM runtime instance
1271  * @cond: condition bits
1272  * @var: hw_params variable to apply the list constraint
1273  * @l: list
1274  *
1275  * Apply the list of constraints to an interval parameter.
1276  *
1277  * Return: Zero if successful, or a negative error code on failure.
1278  */
1279 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
1280                                unsigned int cond,
1281                                snd_pcm_hw_param_t var,
1282                                const struct snd_pcm_hw_constraint_list *l)
1283 {
1284         return snd_pcm_hw_rule_add(runtime, cond, var,
1285                                    snd_pcm_hw_rule_list, (void *)l,
1286                                    var, -1);
1287 }
1288
1289 EXPORT_SYMBOL(snd_pcm_hw_constraint_list);
1290
1291 static int snd_pcm_hw_rule_ranges(struct snd_pcm_hw_params *params,
1292                                   struct snd_pcm_hw_rule *rule)
1293 {
1294         struct snd_pcm_hw_constraint_ranges *r = rule->private;
1295         return snd_interval_ranges(hw_param_interval(params, rule->var),
1296                                    r->count, r->ranges, r->mask);
1297 }
1298
1299
1300 /**
1301  * snd_pcm_hw_constraint_ranges - apply list of range constraints to a parameter
1302  * @runtime: PCM runtime instance
1303  * @cond: condition bits
1304  * @var: hw_params variable to apply the list of range constraints
1305  * @r: ranges
1306  *
1307  * Apply the list of range constraints to an interval parameter.
1308  *
1309  * Return: Zero if successful, or a negative error code on failure.
1310  */
1311 int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime,
1312                                  unsigned int cond,
1313                                  snd_pcm_hw_param_t var,
1314                                  const struct snd_pcm_hw_constraint_ranges *r)
1315 {
1316         return snd_pcm_hw_rule_add(runtime, cond, var,
1317                                    snd_pcm_hw_rule_ranges, (void *)r,
1318                                    var, -1);
1319 }
1320 EXPORT_SYMBOL(snd_pcm_hw_constraint_ranges);
1321
1322 static int snd_pcm_hw_rule_ratnums(struct snd_pcm_hw_params *params,
1323                                    struct snd_pcm_hw_rule *rule)
1324 {
1325         const struct snd_pcm_hw_constraint_ratnums *r = rule->private;
1326         unsigned int num = 0, den = 0;
1327         int err;
1328         err = snd_interval_ratnum(hw_param_interval(params, rule->var),
1329                                   r->nrats, r->rats, &num, &den);
1330         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1331                 params->rate_num = num;
1332                 params->rate_den = den;
1333         }
1334         return err;
1335 }
1336
1337 /**
1338  * snd_pcm_hw_constraint_ratnums - apply ratnums constraint to a parameter
1339  * @runtime: PCM runtime instance
1340  * @cond: condition bits
1341  * @var: hw_params variable to apply the ratnums constraint
1342  * @r: struct snd_ratnums constriants
1343  *
1344  * Return: Zero if successful, or a negative error code on failure.
1345  */
1346 int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime,
1347                                   unsigned int cond,
1348                                   snd_pcm_hw_param_t var,
1349                                   const struct snd_pcm_hw_constraint_ratnums *r)
1350 {
1351         return snd_pcm_hw_rule_add(runtime, cond, var,
1352                                    snd_pcm_hw_rule_ratnums, (void *)r,
1353                                    var, -1);
1354 }
1355
1356 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratnums);
1357
1358 static int snd_pcm_hw_rule_ratdens(struct snd_pcm_hw_params *params,
1359                                    struct snd_pcm_hw_rule *rule)
1360 {
1361         const struct snd_pcm_hw_constraint_ratdens *r = rule->private;
1362         unsigned int num = 0, den = 0;
1363         int err = snd_interval_ratden(hw_param_interval(params, rule->var),
1364                                   r->nrats, r->rats, &num, &den);
1365         if (err >= 0 && den && rule->var == SNDRV_PCM_HW_PARAM_RATE) {
1366                 params->rate_num = num;
1367                 params->rate_den = den;
1368         }
1369         return err;
1370 }
1371
1372 /**
1373  * snd_pcm_hw_constraint_ratdens - apply ratdens constraint to a parameter
1374  * @runtime: PCM runtime instance
1375  * @cond: condition bits
1376  * @var: hw_params variable to apply the ratdens constraint
1377  * @r: struct snd_ratdens constriants
1378  *
1379  * Return: Zero if successful, or a negative error code on failure.
1380  */
1381 int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime,
1382                                   unsigned int cond,
1383                                   snd_pcm_hw_param_t var,
1384                                   const struct snd_pcm_hw_constraint_ratdens *r)
1385 {
1386         return snd_pcm_hw_rule_add(runtime, cond, var,
1387                                    snd_pcm_hw_rule_ratdens, (void *)r,
1388                                    var, -1);
1389 }
1390
1391 EXPORT_SYMBOL(snd_pcm_hw_constraint_ratdens);
1392
1393 static int snd_pcm_hw_rule_msbits(struct snd_pcm_hw_params *params,
1394                                   struct snd_pcm_hw_rule *rule)
1395 {
1396         unsigned int l = (unsigned long) rule->private;
1397         int width = l & 0xffff;
1398         unsigned int msbits = l >> 16;
1399         const struct snd_interval *i =
1400                 hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS);
1401
1402         if (!snd_interval_single(i))
1403                 return 0;
1404
1405         if ((snd_interval_value(i) == width) ||
1406             (width == 0 && snd_interval_value(i) > msbits))
1407                 params->msbits = min_not_zero(params->msbits, msbits);
1408
1409         return 0;
1410 }
1411
1412 /**
1413  * snd_pcm_hw_constraint_msbits - add a hw constraint msbits rule
1414  * @runtime: PCM runtime instance
1415  * @cond: condition bits
1416  * @width: sample bits width
1417  * @msbits: msbits width
1418  *
1419  * This constraint will set the number of most significant bits (msbits) if a
1420  * sample format with the specified width has been select. If width is set to 0
1421  * the msbits will be set for any sample format with a width larger than the
1422  * specified msbits.
1423  *
1424  * Return: Zero if successful, or a negative error code on failure.
1425  */
1426 int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime,
1427                                  unsigned int cond,
1428                                  unsigned int width,
1429                                  unsigned int msbits)
1430 {
1431         unsigned long l = (msbits << 16) | width;
1432         return snd_pcm_hw_rule_add(runtime, cond, -1,
1433                                     snd_pcm_hw_rule_msbits,
1434                                     (void*) l,
1435                                     SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
1436 }
1437
1438 EXPORT_SYMBOL(snd_pcm_hw_constraint_msbits);
1439
1440 static int snd_pcm_hw_rule_step(struct snd_pcm_hw_params *params,
1441                                 struct snd_pcm_hw_rule *rule)
1442 {
1443         unsigned long step = (unsigned long) rule->private;
1444         return snd_interval_step(hw_param_interval(params, rule->var), step);
1445 }
1446
1447 /**
1448  * snd_pcm_hw_constraint_step - add a hw constraint step rule
1449  * @runtime: PCM runtime instance
1450  * @cond: condition bits
1451  * @var: hw_params variable to apply the step constraint
1452  * @step: step size
1453  *
1454  * Return: Zero if successful, or a negative error code on failure.
1455  */
1456 int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
1457                                unsigned int cond,
1458                                snd_pcm_hw_param_t var,
1459                                unsigned long step)
1460 {
1461         return snd_pcm_hw_rule_add(runtime, cond, var,
1462                                    snd_pcm_hw_rule_step, (void *) step,
1463                                    var, -1);
1464 }
1465
1466 EXPORT_SYMBOL(snd_pcm_hw_constraint_step);
1467
1468 static int snd_pcm_hw_rule_pow2(struct snd_pcm_hw_params *params, struct snd_pcm_hw_rule *rule)
1469 {
1470         static unsigned int pow2_sizes[] = {
1471                 1<<0, 1<<1, 1<<2, 1<<3, 1<<4, 1<<5, 1<<6, 1<<7,
1472                 1<<8, 1<<9, 1<<10, 1<<11, 1<<12, 1<<13, 1<<14, 1<<15,
1473                 1<<16, 1<<17, 1<<18, 1<<19, 1<<20, 1<<21, 1<<22, 1<<23,
1474                 1<<24, 1<<25, 1<<26, 1<<27, 1<<28, 1<<29, 1<<30
1475         };
1476         return snd_interval_list(hw_param_interval(params, rule->var),
1477                                  ARRAY_SIZE(pow2_sizes), pow2_sizes, 0);
1478 }
1479
1480 /**
1481  * snd_pcm_hw_constraint_pow2 - add a hw constraint power-of-2 rule
1482  * @runtime: PCM runtime instance
1483  * @cond: condition bits
1484  * @var: hw_params variable to apply the power-of-2 constraint
1485  *
1486  * Return: Zero if successful, or a negative error code on failure.
1487  */
1488 int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
1489                                unsigned int cond,
1490                                snd_pcm_hw_param_t var)
1491 {
1492         return snd_pcm_hw_rule_add(runtime, cond, var,
1493                                    snd_pcm_hw_rule_pow2, NULL,
1494                                    var, -1);
1495 }
1496
1497 EXPORT_SYMBOL(snd_pcm_hw_constraint_pow2);
1498
1499 static int snd_pcm_hw_rule_noresample_func(struct snd_pcm_hw_params *params,
1500                                            struct snd_pcm_hw_rule *rule)
1501 {
1502         unsigned int base_rate = (unsigned int)(uintptr_t)rule->private;
1503         struct snd_interval *rate;
1504
1505         rate = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
1506         return snd_interval_list(rate, 1, &base_rate, 0);
1507 }
1508
1509 /**
1510  * snd_pcm_hw_rule_noresample - add a rule to allow disabling hw resampling
1511  * @runtime: PCM runtime instance
1512  * @base_rate: the rate at which the hardware does not resample
1513  *
1514  * Return: Zero if successful, or a negative error code on failure.
1515  */
1516 int snd_pcm_hw_rule_noresample(struct snd_pcm_runtime *runtime,
1517                                unsigned int base_rate)
1518 {
1519         return snd_pcm_hw_rule_add(runtime, SNDRV_PCM_HW_PARAMS_NORESAMPLE,
1520                                    SNDRV_PCM_HW_PARAM_RATE,
1521                                    snd_pcm_hw_rule_noresample_func,
1522                                    (void *)(uintptr_t)base_rate,
1523                                    SNDRV_PCM_HW_PARAM_RATE, -1);
1524 }
1525 EXPORT_SYMBOL(snd_pcm_hw_rule_noresample);
1526
1527 static void _snd_pcm_hw_param_any(struct snd_pcm_hw_params *params,
1528                                   snd_pcm_hw_param_t var)
1529 {
1530         if (hw_is_mask(var)) {
1531                 snd_mask_any(hw_param_mask(params, var));
1532                 params->cmask |= 1 << var;
1533                 params->rmask |= 1 << var;
1534                 return;
1535         }
1536         if (hw_is_interval(var)) {
1537                 snd_interval_any(hw_param_interval(params, var));
1538                 params->cmask |= 1 << var;
1539                 params->rmask |= 1 << var;
1540                 return;
1541         }
1542         snd_BUG();
1543 }
1544
1545 void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params)
1546 {
1547         unsigned int k;
1548         memset(params, 0, sizeof(*params));
1549         for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++)
1550                 _snd_pcm_hw_param_any(params, k);
1551         for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++)
1552                 _snd_pcm_hw_param_any(params, k);
1553         params->info = ~0U;
1554 }
1555
1556 EXPORT_SYMBOL(_snd_pcm_hw_params_any);
1557
1558 /**
1559  * snd_pcm_hw_param_value - return @params field @var value
1560  * @params: the hw_params instance
1561  * @var: parameter to retrieve
1562  * @dir: pointer to the direction (-1,0,1) or %NULL
1563  *
1564  * Return: The value for field @var if it's fixed in configuration space
1565  * defined by @params. -%EINVAL otherwise.
1566  */
1567 int snd_pcm_hw_param_value(const struct snd_pcm_hw_params *params,
1568                            snd_pcm_hw_param_t var, int *dir)
1569 {
1570         if (hw_is_mask(var)) {
1571                 const struct snd_mask *mask = hw_param_mask_c(params, var);
1572                 if (!snd_mask_single(mask))
1573                         return -EINVAL;
1574                 if (dir)
1575                         *dir = 0;
1576                 return snd_mask_value(mask);
1577         }
1578         if (hw_is_interval(var)) {
1579                 const struct snd_interval *i = hw_param_interval_c(params, var);
1580                 if (!snd_interval_single(i))
1581                         return -EINVAL;
1582                 if (dir)
1583                         *dir = i->openmin;
1584                 return snd_interval_value(i);
1585         }
1586         return -EINVAL;
1587 }
1588
1589 EXPORT_SYMBOL(snd_pcm_hw_param_value);
1590
1591 void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params,
1592                                 snd_pcm_hw_param_t var)
1593 {
1594         if (hw_is_mask(var)) {
1595                 snd_mask_none(hw_param_mask(params, var));
1596                 params->cmask |= 1 << var;
1597                 params->rmask |= 1 << var;
1598         } else if (hw_is_interval(var)) {
1599                 snd_interval_none(hw_param_interval(params, var));
1600                 params->cmask |= 1 << var;
1601                 params->rmask |= 1 << var;
1602         } else {
1603                 snd_BUG();
1604         }
1605 }
1606
1607 EXPORT_SYMBOL(_snd_pcm_hw_param_setempty);
1608
1609 static int _snd_pcm_hw_param_first(struct snd_pcm_hw_params *params,
1610                                    snd_pcm_hw_param_t var)
1611 {
1612         int changed;
1613         if (hw_is_mask(var))
1614                 changed = snd_mask_refine_first(hw_param_mask(params, var));
1615         else if (hw_is_interval(var))
1616                 changed = snd_interval_refine_first(hw_param_interval(params, var));
1617         else
1618                 return -EINVAL;
1619         if (changed) {
1620                 params->cmask |= 1 << var;
1621                 params->rmask |= 1 << var;
1622         }
1623         return changed;
1624 }
1625
1626
1627 /**
1628  * snd_pcm_hw_param_first - refine config space and return minimum value
1629  * @pcm: PCM instance
1630  * @params: the hw_params instance
1631  * @var: parameter to retrieve
1632  * @dir: pointer to the direction (-1,0,1) or %NULL
1633  *
1634  * Inside configuration space defined by @params remove from @var all
1635  * values > minimum. Reduce configuration space accordingly.
1636  *
1637  * Return: The minimum, or a negative error code on failure.
1638  */
1639 int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm,
1640                            struct snd_pcm_hw_params *params,
1641                            snd_pcm_hw_param_t var, int *dir)
1642 {
1643         int changed = _snd_pcm_hw_param_first(params, var);
1644         if (changed < 0)
1645                 return changed;
1646         if (params->rmask) {
1647                 int err = snd_pcm_hw_refine(pcm, params);
1648                 if (snd_BUG_ON(err < 0))
1649                         return err;
1650         }
1651         return snd_pcm_hw_param_value(params, var, dir);
1652 }
1653
1654 EXPORT_SYMBOL(snd_pcm_hw_param_first);
1655
1656 static int _snd_pcm_hw_param_last(struct snd_pcm_hw_params *params,
1657                                   snd_pcm_hw_param_t var)
1658 {
1659         int changed;
1660         if (hw_is_mask(var))
1661                 changed = snd_mask_refine_last(hw_param_mask(params, var));
1662         else if (hw_is_interval(var))
1663                 changed = snd_interval_refine_last(hw_param_interval(params, var));
1664         else
1665                 return -EINVAL;
1666         if (changed) {
1667                 params->cmask |= 1 << var;
1668                 params->rmask |= 1 << var;
1669         }
1670         return changed;
1671 }
1672
1673
1674 /**
1675  * snd_pcm_hw_param_last - refine config space and return maximum value
1676  * @pcm: PCM instance
1677  * @params: the hw_params instance
1678  * @var: parameter to retrieve
1679  * @dir: pointer to the direction (-1,0,1) or %NULL
1680  *
1681  * Inside configuration space defined by @params remove from @var all
1682  * values < maximum. Reduce configuration space accordingly.
1683  *
1684  * Return: The maximum, or a negative error code on failure.
1685  */
1686 int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm,
1687                           struct snd_pcm_hw_params *params,
1688                           snd_pcm_hw_param_t var, int *dir)
1689 {
1690         int changed = _snd_pcm_hw_param_last(params, var);
1691         if (changed < 0)
1692                 return changed;
1693         if (params->rmask) {
1694                 int err = snd_pcm_hw_refine(pcm, params);
1695                 if (snd_BUG_ON(err < 0))
1696                         return err;
1697         }
1698         return snd_pcm_hw_param_value(params, var, dir);
1699 }
1700
1701 EXPORT_SYMBOL(snd_pcm_hw_param_last);
1702
1703 /**
1704  * snd_pcm_hw_param_choose - choose a configuration defined by @params
1705  * @pcm: PCM instance
1706  * @params: the hw_params instance
1707  *
1708  * Choose one configuration from configuration space defined by @params.
1709  * The configuration chosen is that obtained fixing in this order:
1710  * first access, first format, first subformat, min channels,
1711  * min rate, min period time, max buffer size, min tick time
1712  *
1713  * Return: Zero if successful, or a negative error code on failure.
1714  */
1715 int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
1716                              struct snd_pcm_hw_params *params)
1717 {
1718         static const int vars[] = {
1719                 SNDRV_PCM_HW_PARAM_ACCESS,
1720                 SNDRV_PCM_HW_PARAM_FORMAT,
1721                 SNDRV_PCM_HW_PARAM_SUBFORMAT,
1722                 SNDRV_PCM_HW_PARAM_CHANNELS,
1723                 SNDRV_PCM_HW_PARAM_RATE,
1724                 SNDRV_PCM_HW_PARAM_PERIOD_TIME,
1725                 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
1726                 SNDRV_PCM_HW_PARAM_TICK_TIME,
1727                 -1
1728         };
1729         const int *v;
1730         int err;
1731
1732         for (v = vars; *v != -1; v++) {
1733                 if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
1734                         err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
1735                 else
1736                         err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
1737                 if (snd_BUG_ON(err < 0))
1738                         return err;
1739         }
1740         return 0;
1741 }
1742
1743 static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream,
1744                                    void *arg)
1745 {
1746         struct snd_pcm_runtime *runtime = substream->runtime;
1747         unsigned long flags;
1748         snd_pcm_stream_lock_irqsave(substream, flags);
1749         if (snd_pcm_running(substream) &&
1750             snd_pcm_update_hw_ptr(substream) >= 0)
1751                 runtime->status->hw_ptr %= runtime->buffer_size;
1752         else {
1753                 runtime->status->hw_ptr = 0;
1754                 runtime->hw_ptr_wrap = 0;
1755         }
1756         snd_pcm_stream_unlock_irqrestore(substream, flags);
1757         return 0;
1758 }
1759
1760 static int snd_pcm_lib_ioctl_channel_info(struct snd_pcm_substream *substream,
1761                                           void *arg)
1762 {
1763         struct snd_pcm_channel_info *info = arg;
1764         struct snd_pcm_runtime *runtime = substream->runtime;
1765         int width;
1766         if (!(runtime->info & SNDRV_PCM_INFO_MMAP)) {
1767                 info->offset = -1;
1768                 return 0;
1769         }
1770         width = snd_pcm_format_physical_width(runtime->format);
1771         if (width < 0)
1772                 return width;
1773         info->offset = 0;
1774         switch (runtime->access) {
1775         case SNDRV_PCM_ACCESS_MMAP_INTERLEAVED:
1776         case SNDRV_PCM_ACCESS_RW_INTERLEAVED:
1777                 info->first = info->channel * width;
1778                 info->step = runtime->channels * width;
1779                 break;
1780         case SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED:
1781         case SNDRV_PCM_ACCESS_RW_NONINTERLEAVED:
1782         {
1783                 size_t size = runtime->dma_bytes / runtime->channels;
1784                 info->first = info->channel * size * 8;
1785                 info->step = width;
1786                 break;
1787         }
1788         default:
1789                 snd_BUG();
1790                 break;
1791         }
1792         return 0;
1793 }
1794
1795 static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream,
1796                                        void *arg)
1797 {
1798         struct snd_pcm_hw_params *params = arg;
1799         snd_pcm_format_t format;
1800         int channels;
1801         ssize_t frame_size;
1802
1803         params->fifo_size = substream->runtime->hw.fifo_size;
1804         if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) {
1805                 format = params_format(params);
1806                 channels = params_channels(params);
1807                 frame_size = snd_pcm_format_size(format, channels);
1808                 if (frame_size > 0)
1809                         params->fifo_size /= (unsigned)frame_size;
1810         }
1811         return 0;
1812 }
1813
1814 /**
1815  * snd_pcm_lib_ioctl - a generic PCM ioctl callback
1816  * @substream: the pcm substream instance
1817  * @cmd: ioctl command
1818  * @arg: ioctl argument
1819  *
1820  * Processes the generic ioctl commands for PCM.
1821  * Can be passed as the ioctl callback for PCM ops.
1822  *
1823  * Return: Zero if successful, or a negative error code on failure.
1824  */
1825 int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
1826                       unsigned int cmd, void *arg)
1827 {
1828         switch (cmd) {
1829         case SNDRV_PCM_IOCTL1_INFO:
1830                 return 0;
1831         case SNDRV_PCM_IOCTL1_RESET:
1832                 return snd_pcm_lib_ioctl_reset(substream, arg);
1833         case SNDRV_PCM_IOCTL1_CHANNEL_INFO:
1834                 return snd_pcm_lib_ioctl_channel_info(substream, arg);
1835         case SNDRV_PCM_IOCTL1_FIFO_SIZE:
1836                 return snd_pcm_lib_ioctl_fifo_size(substream, arg);
1837         }
1838         return -ENXIO;
1839 }
1840
1841 EXPORT_SYMBOL(snd_pcm_lib_ioctl);
1842
1843 /**
1844  * snd_pcm_period_elapsed - update the pcm status for the next period
1845  * @substream: the pcm substream instance
1846  *
1847  * This function is called from the interrupt handler when the
1848  * PCM has processed the period size.  It will update the current
1849  * pointer, wake up sleepers, etc.
1850  *
1851  * Even if more than one periods have elapsed since the last call, you
1852  * have to call this only once.
1853  */
1854 void snd_pcm_period_elapsed(struct snd_pcm_substream *substream)
1855 {
1856         struct snd_pcm_runtime *runtime;
1857         unsigned long flags;
1858
1859         if (PCM_RUNTIME_CHECK(substream))
1860                 return;
1861         runtime = substream->runtime;
1862
1863         snd_pcm_stream_lock_irqsave(substream, flags);
1864         if (!snd_pcm_running(substream) ||
1865             snd_pcm_update_hw_ptr0(substream, 1) < 0)
1866                 goto _end;
1867
1868 #ifdef CONFIG_SND_PCM_TIMER
1869         if (substream->timer_running)
1870                 snd_timer_interrupt(substream->timer, 1);
1871 #endif
1872  _end:
1873         kill_fasync(&runtime->fasync, SIGIO, POLL_IN);
1874         snd_pcm_stream_unlock_irqrestore(substream, flags);
1875 }
1876
1877 EXPORT_SYMBOL(snd_pcm_period_elapsed);
1878
1879 /*
1880  * Wait until avail_min data becomes available
1881  * Returns a negative error code if any error occurs during operation.
1882  * The available space is stored on availp.  When err = 0 and avail = 0
1883  * on the capture stream, it indicates the stream is in DRAINING state.
1884  */
1885 static int wait_for_avail(struct snd_pcm_substream *substream,
1886                               snd_pcm_uframes_t *availp)
1887 {
1888         struct snd_pcm_runtime *runtime = substream->runtime;
1889         int is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
1890         wait_queue_t wait;
1891         int err = 0;
1892         snd_pcm_uframes_t avail = 0;
1893         long wait_time, tout;
1894
1895         init_waitqueue_entry(&wait, current);
1896         set_current_state(TASK_INTERRUPTIBLE);
1897         add_wait_queue(&runtime->tsleep, &wait);
1898
1899         if (runtime->no_period_wakeup)
1900                 wait_time = MAX_SCHEDULE_TIMEOUT;
1901         else {
1902                 wait_time = 10;
1903                 if (runtime->rate) {
1904                         long t = runtime->period_size * 2 / runtime->rate;
1905                         wait_time = max(t, wait_time);
1906                 }
1907                 wait_time = msecs_to_jiffies(wait_time * 1000);
1908         }
1909
1910         for (;;) {
1911                 if (signal_pending(current)) {
1912                         err = -ERESTARTSYS;
1913                         break;
1914                 }
1915
1916                 /*
1917                  * We need to check if space became available already
1918                  * (and thus the wakeup happened already) first to close
1919                  * the race of space already having become available.
1920                  * This check must happen after been added to the waitqueue
1921                  * and having current state be INTERRUPTIBLE.
1922                  */
1923                 if (is_playback)
1924                         avail = snd_pcm_playback_avail(runtime);
1925                 else
1926                         avail = snd_pcm_capture_avail(runtime);
1927                 if (avail >= runtime->twake)
1928                         break;
1929                 snd_pcm_stream_unlock_irq(substream);
1930
1931                 tout = schedule_timeout(wait_time);
1932
1933                 snd_pcm_stream_lock_irq(substream);
1934                 set_current_state(TASK_INTERRUPTIBLE);
1935                 switch (runtime->status->state) {
1936                 case SNDRV_PCM_STATE_SUSPENDED:
1937                         err = -ESTRPIPE;
1938                         goto _endloop;
1939                 case SNDRV_PCM_STATE_XRUN:
1940                         err = -EPIPE;
1941                         goto _endloop;
1942                 case SNDRV_PCM_STATE_DRAINING:
1943                         if (is_playback)
1944                                 err = -EPIPE;
1945                         else
1946                                 avail = 0; /* indicate draining */
1947                         goto _endloop;
1948                 case SNDRV_PCM_STATE_OPEN:
1949                 case SNDRV_PCM_STATE_SETUP:
1950                 case SNDRV_PCM_STATE_DISCONNECTED:
1951                         err = -EBADFD;
1952                         goto _endloop;
1953                 case SNDRV_PCM_STATE_PAUSED:
1954                         continue;
1955                 }
1956                 if (!tout) {
1957                         pcm_dbg(substream->pcm,
1958                                 "%s write error (DMA or IRQ trouble?)\n",
1959                                 is_playback ? "playback" : "capture");
1960                         err = -EIO;
1961                         break;
1962                 }
1963         }
1964  _endloop:
1965         set_current_state(TASK_RUNNING);
1966         remove_wait_queue(&runtime->tsleep, &wait);
1967         *availp = avail;
1968         return err;
1969 }
1970
1971 typedef int (*pcm_transfer_f)(struct snd_pcm_substream *substream,
1972                               int channel, unsigned long hwoff,
1973                               void *buf, unsigned long bytes);
1974
1975 typedef int (*pcm_copy_f)(struct snd_pcm_substream *, snd_pcm_uframes_t, void *,
1976                           snd_pcm_uframes_t, snd_pcm_uframes_t, pcm_transfer_f);
1977
1978 /* calculate the target DMA-buffer position to be written/read */
1979 static void *get_dma_ptr(struct snd_pcm_runtime *runtime,
1980                            int channel, unsigned long hwoff)
1981 {
1982         return runtime->dma_area + hwoff +
1983                 channel * (runtime->dma_bytes / runtime->channels);
1984 }
1985
1986 /* default copy_user ops for write; used for both interleaved and non- modes */
1987 static int default_write_copy(struct snd_pcm_substream *substream,
1988                               int channel, unsigned long hwoff,
1989                               void *buf, unsigned long bytes)
1990 {
1991         if (copy_from_user(get_dma_ptr(substream->runtime, channel, hwoff),
1992                            (void __user *)buf, bytes))
1993                 return -EFAULT;
1994         return 0;
1995 }
1996
1997 /* fill silence instead of copy data; called as a transfer helper
1998  * from __snd_pcm_lib_write() or directly from noninterleaved_copy() when
1999  * a NULL buffer is passed
2000  */
2001 static int fill_silence(struct snd_pcm_substream *substream, int channel,
2002                         unsigned long hwoff, void *buf, unsigned long bytes)
2003 {
2004         struct snd_pcm_runtime *runtime = substream->runtime;
2005
2006         if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
2007                 return 0;
2008         if (substream->ops->fill_silence)
2009                 return substream->ops->fill_silence(substream, channel,
2010                                                     hwoff, bytes);
2011
2012         snd_pcm_format_set_silence(runtime->format,
2013                                    get_dma_ptr(runtime, channel, hwoff),
2014                                    bytes_to_samples(runtime, bytes));
2015         return 0;
2016 }
2017
2018 /* default copy_user ops for read; used for both interleaved and non- modes */
2019 static int default_read_copy(struct snd_pcm_substream *substream,
2020                              int channel, unsigned long hwoff,
2021                              void *buf, unsigned long bytes)
2022 {
2023         if (copy_to_user((void __user *)buf,
2024                          get_dma_ptr(substream->runtime, channel, hwoff),
2025                          bytes))
2026                 return -EFAULT;
2027         return 0;
2028 }
2029
2030 /* call transfer function with the converted pointers and sizes;
2031  * for interleaved mode, it's one shot for all samples
2032  */
2033 static int interleaved_copy(struct snd_pcm_substream *substream,
2034                             snd_pcm_uframes_t hwoff, void *data,
2035                             snd_pcm_uframes_t off,
2036                             snd_pcm_uframes_t frames,
2037                             pcm_transfer_f transfer)
2038 {
2039         struct snd_pcm_runtime *runtime = substream->runtime;
2040
2041         /* convert to bytes */
2042         hwoff = frames_to_bytes(runtime, hwoff);
2043         off = frames_to_bytes(runtime, off);
2044         frames = frames_to_bytes(runtime, frames);
2045         return transfer(substream, 0, hwoff, data + off, frames);
2046 }
2047
2048 /* call transfer function with the converted pointers and sizes for each
2049  * non-interleaved channel; when buffer is NULL, silencing instead of copying
2050  */
2051 static int noninterleaved_copy(struct snd_pcm_substream *substream,
2052                                snd_pcm_uframes_t hwoff, void *data,
2053                                snd_pcm_uframes_t off,
2054                                snd_pcm_uframes_t frames,
2055                                pcm_transfer_f transfer)
2056 {
2057         struct snd_pcm_runtime *runtime = substream->runtime;
2058         int channels = runtime->channels;
2059         void **bufs = data;
2060         int c, err;
2061
2062         /* convert to bytes; note that it's not frames_to_bytes() here.
2063          * in non-interleaved mode, we copy for each channel, thus
2064          * each copy is n_samples bytes x channels = whole frames.
2065          */
2066         off = samples_to_bytes(runtime, off);
2067         frames = samples_to_bytes(runtime, frames);
2068         hwoff = samples_to_bytes(runtime, hwoff);
2069         for (c = 0; c < channels; ++c, ++bufs) {
2070                 if (!data || !*bufs)
2071                         err = fill_silence(substream, c, hwoff, NULL, frames);
2072                 else
2073                         err = transfer(substream, c, hwoff, *bufs + off,
2074                                        frames);
2075                 if (err < 0)
2076                         return err;
2077         }
2078         return 0;
2079 }
2080
2081 /* fill silence on the given buffer position;
2082  * called from snd_pcm_playback_silence()
2083  */
2084 static int fill_silence_frames(struct snd_pcm_substream *substream,
2085                                snd_pcm_uframes_t off, snd_pcm_uframes_t frames)
2086 {
2087         if (substream->runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
2088             substream->runtime->access == SNDRV_PCM_ACCESS_MMAP_INTERLEAVED)
2089                 return interleaved_copy(substream, off, NULL, 0, frames,
2090                                         fill_silence);
2091         else
2092                 return noninterleaved_copy(substream, off, NULL, 0, frames,
2093                                            fill_silence);
2094 }
2095
2096 /* sanity-check for read/write methods */
2097 static int pcm_sanity_check(struct snd_pcm_substream *substream)
2098 {
2099         struct snd_pcm_runtime *runtime;
2100         if (PCM_RUNTIME_CHECK(substream))
2101                 return -ENXIO;
2102         runtime = substream->runtime;
2103         if (snd_BUG_ON(!substream->ops->copy_user && !runtime->dma_area))
2104                 return -EINVAL;
2105         if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
2106                 return -EBADFD;
2107         return 0;
2108 }
2109
2110 static int pcm_accessible_state(struct snd_pcm_runtime *runtime)
2111 {
2112         switch (runtime->status->state) {
2113         case SNDRV_PCM_STATE_PREPARED:
2114         case SNDRV_PCM_STATE_RUNNING:
2115         case SNDRV_PCM_STATE_PAUSED:
2116                 return 0;
2117         case SNDRV_PCM_STATE_XRUN:
2118                 return -EPIPE;
2119         case SNDRV_PCM_STATE_SUSPENDED:
2120                 return -ESTRPIPE;
2121         default:
2122                 return -EBADFD;
2123         }
2124 }
2125
2126 /* the common loop for read/write data */
2127 snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream,
2128                                      void *data, bool interleaved,
2129                                      snd_pcm_uframes_t size)
2130 {
2131         struct snd_pcm_runtime *runtime = substream->runtime;
2132         snd_pcm_uframes_t xfer = 0;
2133         snd_pcm_uframes_t offset = 0;
2134         snd_pcm_uframes_t avail;
2135         pcm_copy_f writer;
2136         pcm_transfer_f transfer;
2137         bool nonblock;
2138         bool is_playback;
2139         int err;
2140
2141         err = pcm_sanity_check(substream);
2142         if (err < 0)
2143                 return err;
2144
2145         is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
2146         if (interleaved) {
2147                 if (runtime->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
2148                     runtime->channels > 1)
2149                         return -EINVAL;
2150                 writer = interleaved_copy;
2151         } else {
2152                 if (runtime->access != SNDRV_PCM_ACCESS_RW_NONINTERLEAVED)
2153                         return -EINVAL;
2154                 writer = noninterleaved_copy;
2155         }
2156
2157         if (!data) {
2158                 if (is_playback)
2159                         transfer = fill_silence;
2160                 else
2161                         return -EINVAL;
2162         } else {
2163                 if (substream->ops->copy_user)
2164                         transfer = (pcm_transfer_f)substream->ops->copy_user;
2165                 else
2166                         transfer = is_playback ?
2167                                 default_write_copy : default_read_copy;
2168         }
2169
2170         if (size == 0)
2171                 return 0;
2172
2173         nonblock = !!(substream->f_flags & O_NONBLOCK);
2174
2175         snd_pcm_stream_lock_irq(substream);
2176         err = pcm_accessible_state(runtime);
2177         if (err < 0)
2178                 goto _end_unlock;
2179
2180         if (!is_playback &&
2181             runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2182             size >= runtime->start_threshold) {
2183                 err = snd_pcm_start(substream);
2184                 if (err < 0)
2185                         goto _end_unlock;
2186         }
2187
2188         runtime->twake = runtime->control->avail_min ? : 1;
2189         if (runtime->status->state == SNDRV_PCM_STATE_RUNNING)
2190                 snd_pcm_update_hw_ptr(substream);
2191         if (is_playback)
2192                 avail = snd_pcm_playback_avail(runtime);
2193         else
2194                 avail = snd_pcm_capture_avail(runtime);
2195         while (size > 0) {
2196                 snd_pcm_uframes_t frames, appl_ptr, appl_ofs;
2197                 snd_pcm_uframes_t cont;
2198                 if (!avail) {
2199                         if (!is_playback &&
2200                             runtime->status->state == SNDRV_PCM_STATE_DRAINING) {
2201                                 snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
2202                                 goto _end_unlock;
2203                         }
2204                         if (nonblock) {
2205                                 err = -EAGAIN;
2206                                 goto _end_unlock;
2207                         }
2208                         runtime->twake = min_t(snd_pcm_uframes_t, size,
2209                                         runtime->control->avail_min ? : 1);
2210                         err = wait_for_avail(substream, &avail);
2211                         if (err < 0)
2212                                 goto _end_unlock;
2213                         if (!avail)
2214                                 continue; /* draining */
2215                 }
2216                 frames = size > avail ? avail : size;
2217                 cont = runtime->buffer_size - runtime->control->appl_ptr % runtime->buffer_size;
2218                 if (frames > cont)
2219                         frames = cont;
2220                 if (snd_BUG_ON(!frames)) {
2221                         runtime->twake = 0;
2222                         snd_pcm_stream_unlock_irq(substream);
2223                         return -EINVAL;
2224                 }
2225                 appl_ptr = runtime->control->appl_ptr;
2226                 appl_ofs = appl_ptr % runtime->buffer_size;
2227                 snd_pcm_stream_unlock_irq(substream);
2228                 err = writer(substream, appl_ofs, data, offset, frames,
2229                              transfer);
2230                 snd_pcm_stream_lock_irq(substream);
2231                 if (err < 0)
2232                         goto _end_unlock;
2233                 err = pcm_accessible_state(runtime);
2234                 if (err < 0)
2235                         goto _end_unlock;
2236                 appl_ptr += frames;
2237                 if (appl_ptr >= runtime->boundary)
2238                         appl_ptr -= runtime->boundary;
2239                 runtime->control->appl_ptr = appl_ptr;
2240                 if (substream->ops->ack)
2241                         substream->ops->ack(substream);
2242
2243                 offset += frames;
2244                 size -= frames;
2245                 xfer += frames;
2246                 avail -= frames;
2247                 if (is_playback &&
2248                     runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
2249                     snd_pcm_playback_hw_avail(runtime) >= (snd_pcm_sframes_t)runtime->start_threshold) {
2250                         err = snd_pcm_start(substream);
2251                         if (err < 0)
2252                                 goto _end_unlock;
2253                 }
2254         }
2255  _end_unlock:
2256         runtime->twake = 0;
2257         if (xfer > 0 && err >= 0)
2258                 snd_pcm_update_state(substream, runtime);
2259         snd_pcm_stream_unlock_irq(substream);
2260         return xfer > 0 ? (snd_pcm_sframes_t)xfer : err;
2261 }
2262 EXPORT_SYMBOL(__snd_pcm_lib_xfer);
2263
2264 /*
2265  * standard channel mapping helpers
2266  */
2267
2268 /* default channel maps for multi-channel playbacks, up to 8 channels */
2269 const struct snd_pcm_chmap_elem snd_pcm_std_chmaps[] = {
2270         { .channels = 1,
2271           .map = { SNDRV_CHMAP_MONO } },
2272         { .channels = 2,
2273           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2274         { .channels = 4,
2275           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2276                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2277         { .channels = 6,
2278           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2279                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2280                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE } },
2281         { .channels = 8,
2282           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2283                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2284                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2285                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2286         { }
2287 };
2288 EXPORT_SYMBOL_GPL(snd_pcm_std_chmaps);
2289
2290 /* alternative channel maps with CLFE <-> surround swapped for 6/8 channels */
2291 const struct snd_pcm_chmap_elem snd_pcm_alt_chmaps[] = {
2292         { .channels = 1,
2293           .map = { SNDRV_CHMAP_MONO } },
2294         { .channels = 2,
2295           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR } },
2296         { .channels = 4,
2297           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2298                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2299         { .channels = 6,
2300           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2301                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2302                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR } },
2303         { .channels = 8,
2304           .map = { SNDRV_CHMAP_FL, SNDRV_CHMAP_FR,
2305                    SNDRV_CHMAP_FC, SNDRV_CHMAP_LFE,
2306                    SNDRV_CHMAP_RL, SNDRV_CHMAP_RR,
2307                    SNDRV_CHMAP_SL, SNDRV_CHMAP_SR } },
2308         { }
2309 };
2310 EXPORT_SYMBOL_GPL(snd_pcm_alt_chmaps);
2311
2312 static bool valid_chmap_channels(const struct snd_pcm_chmap *info, int ch)
2313 {
2314         if (ch > info->max_channels)
2315                 return false;
2316         return !info->channel_mask || (info->channel_mask & (1U << ch));
2317 }
2318
2319 static int pcm_chmap_ctl_info(struct snd_kcontrol *kcontrol,
2320                               struct snd_ctl_elem_info *uinfo)
2321 {
2322         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2323
2324         uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
2325         uinfo->count = 0;
2326         uinfo->count = info->max_channels;
2327         uinfo->value.integer.min = 0;
2328         uinfo->value.integer.max = SNDRV_CHMAP_LAST;
2329         return 0;
2330 }
2331
2332 /* get callback for channel map ctl element
2333  * stores the channel position firstly matching with the current channels
2334  */
2335 static int pcm_chmap_ctl_get(struct snd_kcontrol *kcontrol,
2336                              struct snd_ctl_elem_value *ucontrol)
2337 {
2338         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2339         unsigned int idx = snd_ctl_get_ioffidx(kcontrol, &ucontrol->id);
2340         struct snd_pcm_substream *substream;
2341         const struct snd_pcm_chmap_elem *map;
2342
2343         if (snd_BUG_ON(!info->chmap))
2344                 return -EINVAL;
2345         substream = snd_pcm_chmap_substream(info, idx);
2346         if (!substream)
2347                 return -ENODEV;
2348         memset(ucontrol->value.integer.value, 0,
2349                sizeof(ucontrol->value.integer.value));
2350         if (!substream->runtime)
2351                 return 0; /* no channels set */
2352         for (map = info->chmap; map->channels; map++) {
2353                 int i;
2354                 if (map->channels == substream->runtime->channels &&
2355                     valid_chmap_channels(info, map->channels)) {
2356                         for (i = 0; i < map->channels; i++)
2357                                 ucontrol->value.integer.value[i] = map->map[i];
2358                         return 0;
2359                 }
2360         }
2361         return -EINVAL;
2362 }
2363
2364 /* tlv callback for channel map ctl element
2365  * expands the pre-defined channel maps in a form of TLV
2366  */
2367 static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
2368                              unsigned int size, unsigned int __user *tlv)
2369 {
2370         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2371         const struct snd_pcm_chmap_elem *map;
2372         unsigned int __user *dst;
2373         int c, count = 0;
2374
2375         if (snd_BUG_ON(!info->chmap))
2376                 return -EINVAL;
2377         if (size < 8)
2378                 return -ENOMEM;
2379         if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
2380                 return -EFAULT;
2381         size -= 8;
2382         dst = tlv + 2;
2383         for (map = info->chmap; map->channels; map++) {
2384                 int chs_bytes = map->channels * 4;
2385                 if (!valid_chmap_channels(info, map->channels))
2386                         continue;
2387                 if (size < 8)
2388                         return -ENOMEM;
2389                 if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
2390                     put_user(chs_bytes, dst + 1))
2391                         return -EFAULT;
2392                 dst += 2;
2393                 size -= 8;
2394                 count += 8;
2395                 if (size < chs_bytes)
2396                         return -ENOMEM;
2397                 size -= chs_bytes;
2398                 count += chs_bytes;
2399                 for (c = 0; c < map->channels; c++) {
2400                         if (put_user(map->map[c], dst))
2401                                 return -EFAULT;
2402                         dst++;
2403                 }
2404         }
2405         if (put_user(count, tlv + 1))
2406                 return -EFAULT;
2407         return 0;
2408 }
2409
2410 static void pcm_chmap_ctl_private_free(struct snd_kcontrol *kcontrol)
2411 {
2412         struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
2413         info->pcm->streams[info->stream].chmap_kctl = NULL;
2414         kfree(info);
2415 }
2416
2417 /**
2418  * snd_pcm_add_chmap_ctls - create channel-mapping control elements
2419  * @pcm: the assigned PCM instance
2420  * @stream: stream direction
2421  * @chmap: channel map elements (for query)
2422  * @max_channels: the max number of channels for the stream
2423  * @private_value: the value passed to each kcontrol's private_value field
2424  * @info_ret: store struct snd_pcm_chmap instance if non-NULL
2425  *
2426  * Create channel-mapping control elements assigned to the given PCM stream(s).
2427  * Return: Zero if successful, or a negative error value.
2428  */
2429 int snd_pcm_add_chmap_ctls(struct snd_pcm *pcm, int stream,
2430                            const struct snd_pcm_chmap_elem *chmap,
2431                            int max_channels,
2432                            unsigned long private_value,
2433                            struct snd_pcm_chmap **info_ret)
2434 {
2435         struct snd_pcm_chmap *info;
2436         struct snd_kcontrol_new knew = {
2437                 .iface = SNDRV_CTL_ELEM_IFACE_PCM,
2438                 .access = SNDRV_CTL_ELEM_ACCESS_READ |
2439                         SNDRV_CTL_ELEM_ACCESS_TLV_READ |
2440                         SNDRV_CTL_ELEM_ACCESS_TLV_CALLBACK,
2441                 .info = pcm_chmap_ctl_info,
2442                 .get = pcm_chmap_ctl_get,
2443                 .tlv.c = pcm_chmap_ctl_tlv,
2444         };
2445         int err;
2446
2447         if (WARN_ON(pcm->streams[stream].chmap_kctl))
2448                 return -EBUSY;
2449         info = kzalloc(sizeof(*info), GFP_KERNEL);
2450         if (!info)
2451                 return -ENOMEM;
2452         info->pcm = pcm;
2453         info->stream = stream;
2454         info->chmap = chmap;
2455         info->max_channels = max_channels;
2456         if (stream == SNDRV_PCM_STREAM_PLAYBACK)
2457                 knew.name = "Playback Channel Map";
2458         else
2459                 knew.name = "Capture Channel Map";
2460         knew.device = pcm->device;
2461         knew.count = pcm->streams[stream].substream_count;
2462         knew.private_value = private_value;
2463         info->kctl = snd_ctl_new1(&knew, info);
2464         if (!info->kctl) {
2465                 kfree(info);
2466                 return -ENOMEM;
2467         }
2468         info->kctl->private_free = pcm_chmap_ctl_private_free;
2469         err = snd_ctl_add(pcm->card, info->kctl);
2470         if (err < 0)
2471                 return err;
2472         pcm->streams[stream].chmap_kctl = info->kctl;
2473         if (info_ret)
2474                 *info_ret = info;
2475         return 0;
2476 }
2477 EXPORT_SYMBOL_GPL(snd_pcm_add_chmap_ctls);